This invention concerns a relay unit used to make or break a power supply circuit. More particularly, this invention relates to a relay unit and a housing unit which combines a number of relay switches in a single package in which a number of relay switches are combined in a single package, and the housing used in the relay unit for the packaging.
In many electrical automobiles the motor, which runs the automobile, is driven by a power supply consisting of a built-in battery. A power supply circuit is actuated by a relay switch which turns the power supply on and off.
Such a power supply circuit is shown in FIG. 11. The DC power of battery E is converted to AC power by inverter IN to drive motor M. In front of inverter IN are capacitor C and resistor R, which constitute a charging circuit.
Relay switch X1 turns the positive electrode on and off. Relay switch X2 turns the positive electrode of charging circuit CR on and off. Relay switch X3 turns the negative electrode on and off. (Since both the positive and negative sides of the power supply can be switched on and off, it would be possible to switch both or to switch only the positive side. If only the positive side is switched, the third relay switch, X3, can be omitted.)
To drive motor M, relay switches X2 and X3 are turned on to charge charging circuit CR. When capacitor C is fully or almost fully charged, motor M is driven by turning relay switch X1 on, and relay switch X2 off.
If relay switches X1, X2 and X3 are all used, each is mounted separately in a fitting such as a relay mounting platform. However, mounting two or three relay switches individually is a difficult task, and the wiring can be extremely troublesome.
When two or three relay switches are to be installed side by side, since the same type of switch is used for all three, the connector terminals will all be at the same height. If their wiring is connected by a bus bar tightened down by a screw, an accidental shock can rotate the bar and cause adjacent connections to short.
The object of this invention is to provide a relay unit and a housing for the unit to be used when a number of relay switches are installed side by side in order to switch a power supply circuit on and off. Such a relay unit would be easy to install and wire, and would prevent accidental short circuits from occurring.
This invention is a relay unit to switch a power supply circuit which comprises the following. A number of compartments are provided in a case with an open top such that one relay fits into each compartment. The relays are placed into these compartments, and a cover is fitted onto the open top of the case. Slits are provided along the upper edge of the case and/or in the cover, through which the connectors attached to the terminals of the various relays can pass. The cover is placed on top of the case with the connectors attached to the terminals of the various relays running through the various slits. On the sides of the exterior of the case mounting, slits are provided through which the case can be fastened to its mounting location.
The relays are relay switches. They may be of the sealed or open type. A number of slits formed by the cut out portion are provided for the connectors to guide out. These slits may be positioned along the upper edge of the case, in the cover, or extending from the case to the cover, or some of them may be in the case and others in the cover.
This configuration serves to improve the isolation by ensuring that the edges of adjacent connectors are separated by a given distance. Because the connectors are fed out through the slits, they cannot be rotated. This configuration thus prevents shorting between adjacent connectors when the relay experiences an accidental impact from the exterior.
Placing one of the mounting slits on the bottom of the case allows the relay to be mounted vertically; placing one of the slits on the side of the case allows it to be mounted sideways. Mounting the relay sideways can be an effective way to use a space requiring a low-height component.
In a preferred embodiment of this invention, the common connector terminal for the relays in the case can be wired inside the unit. This will simplify the wiring that must be done on site.
In a preferred embodiment of this invention, the interior of the unit can be filled with insulating resin. In addition to improving the isolation, this will allow the heat generated by the relays to be transmitted to the case and the cover, where it can be radiated effectively via the large surface area.
The housing according to this invention is distinguished by the following. It encloses a relay unit for switching a power supply circuit. It has a case with an open top, which is provided with a plurality of compartments to enclose a plurality of relays, and a cover to be fitted onto the open top of the case. A plurality of cut out portions are provided on at least one upper edge of the case and lower edge of the cover. Through the cut out portion, a plurality of connectors are connected to terminals on relays enclosed in the compartments to guide out from the case when the case is enclosed by the cover. It also has a mounting tab provided on an outer surface of the case for fixing the relay unit.
This design produces a relay unit housing whose isolation is improved by the fact that the edges of adjacent connectors are separated by a given distance. Because the connectors are fed out through the slits, adjacent connectors will not short out when the relay experiences an accidental impact from the exterior.
According to this invention, a number of relay switches are put into a single package (housing), thus making the relays easier to handle. The package makes it easier to mount and wire multiple relay switches. Because the positions of the connectors are controlled by the slits in the case, the connectors cannot rotate if they receive an accidental impact. This prevents accidental short circuits. The case and the cover protect the contacts of the relays"" connectors from water.